Phys.org July 19, 2024 Rare-earth elements with strong magneto-crystalline anisotropy (MCA) are important ingredients for magnetic devices. Control of their localized 4f magnetic moments and anisotropy is one major challenge in ultrafast spin physics. An international team of researchers (Germany, Czech Republic, France, Sweden) used time-resolved x-ray absorption and resonant inelastic scattering experiments to show that for terbium that 4f-electronic excitations out of the ground-state multiplet occurred after optical pumping. These excitations were driven by inelastic 5d-4f-electron scattering, altering the 4f-orbital state and consequently the MCA with important implications for magnetization dynamics in 4f-metals and more general for the excitation […]
A novel thermal insulation material for ultra-high temperature applications: Hierarchical porous high-entropy ceramics
Phys.org July 22, 2024 To meet the emerging demands for thermal protection materials is a critical challenge. Researchers in China developed a novel porous high-entropy carbide (PHEC) ceramic fabricated by a self-foaming method using commercially available metal chloride and furfuryl alcohol as the precursor. The PHEC ceramic was constructed by microspheres with a size of 2 µm, high porosity and an interconnected frame. The microspheres consisted of high-entropy carbide grains resulting in abundant interface and nanosized pores in the PHEC ceramic. It has outstanding compressive strength and exceptionally low thermal conductivity at room temperature. According to the researchers their work […]
Proton-conducting materials could enable new green energy technologies
MIT News July 23, 2024 A quantitative understanding of the physical traits of a material that regulates proton diffusion is necessary for accelerating the discovery of fast proton conductors which is key for advancing many electrochemical technologies. A team of researchers in the US (MIT, Auburn University, Northwestern University) mapped the structural, chemical and dynamic properties of solid acids to the elementary steps of the Grotthuss mechanism of proton diffusion by combining ab initio molecular dynamics simulations, analysis of phonon spectra and atomic structure calculations. They identified the donor–hydrogen bond lengths and the acidity of polyanion groups as key descriptors […]
Researchers zero in on the underlying mechanism that causes alloys to crack when exposed to hydrogen-rich environments
Phys.org July 19, 2024 Researchers at Texas A&M University conducted in situ tensile straining experiments to investigate the role of hydrogen and slip in crack initiation in nickel-based alloy 725. The experiments revealed no tendency for hydrogen to enhance localized slip and no necessity of slip for crack initiation. Using electrochemical charging introduced hydrogen into samples, melted extraction was used to measure hydrogen content. Image correlation analyzed localized plastic strains during in situ tensile tests. Cracks initiated both in regions with and without nearby localized slip. The fraction of cracks initiating with no nearby slip was greater at higher hydrogen […]
Scientists develop fridge-free storage approach for vital medicines
Phys.org July 17, 2024 Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. A team of researchers in the UK designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules could be loaded at up to 10 wt% without affecting the mechanism of release. According to the researchers this […]
Scientists say sun’s influence penetrates into deep Earth
Phys.org July 23, 2024 Vanadium and scandium levels of arc magma served as key indicators in the geochemical models. By compiling global geochemical data from Cenozoic arc magma and olivine-hosted melt inclusions, researchers at the University of Arizona found a latitude-dependent redox distribution of arc magma with less oxidized magma in lower latitudes compared to those in higher latitudes. Based on their work the researchers proposed that such a latitude-dependent pattern in the arc mantle may be controlled by the variation in the redox state of subducted sediment, possibly related to a latitudinal variation in the primary production of phytoplankton, […]
Sea ice’s cooling power is waning faster than its area of extent, new study finds
Phys.org July 17, 2024 Sea ice cools Earth by reducing its absorbed solar energy. An international team of researchers (USA – University of Michigan, Finland) combined radiative transfer modeling with satellite-derived surface albedo, sea ice, and cloud distributions to quantify the top-of-atmosphere sea ice radiative effect (SIRE). The Arctic Sea ice radiative effect has weakened by about 24%, since 1980. The planetary cooling effects of Arctic and Antarctic Sea ice during 2016–2023 were about 20% and 12% less, respectively, than they were during 1980–1988. Arctic SIRE has weakened, implying a 21%–27% reduction in the reflective power of Arctic Sea ice […]
Study unveils complexity of zoonotic transmission chains
Phys.org July 15, 2024 The eco-epidemiology of zoonoses is often oversimplified to host-pathogen interactions while findings derived from global datasets are rarely directly transferable to smaller-scale contexts. Researchers in Austria compiled a dataset of naturally occurring zoonotic interactions in Austria, spanning 1975–2022 and introduced zoonotic web to describe the complex relationships between zoonotic agents, their hosts, vectors, food, and environmental sources. They demonstrated that the most influential zoonotic sources were human, cattle, chicken, and some meat products confirming the increased probability of zoonotic spillover at human-cattle and human-food interfaces. They characterized six communities of zoonotic agent sharing driven by highly […]
Top 10 Science and Technology Inventions for the Week of July 19, 2024
01. A new metamaterial concept offering the potential for more efficient data storage 02. High-speed electron camera uncovers new ‘light-twisting’ behavior in ultrathin material 03. Engineers develop advanced optical computing method for multiplexed data processing and encryption 04. Moving from the visible to the infrared: Developing high quality nanocrystals 05. New method achieves tenfold increase in quantum coherence time via destructive interference of correlated noise 06. Scientists develop new AI method to create material ‘fingerprints’ 07. Scientists develop new technique for bespoke optical tweezers 08. Scientists call for ‘major initiative’ to study whether geoengineering should be used on glaciers 09. […]
Aerosols shown to increase size of cloud cells, causing greater radiative cooling under polluted conditions
Phys.org July 9, 2024 Researchers at Pacific Northwest National Laboratory reconfigured the Weather Research Forecasting (WRF) version 4.3 model to quantify the impact of aerosols on evolving cloud fields. Simulations utilizing meteorological boundary conditions were based on 10 case study days offering diverse meteorology during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA). Measurements demonstrated good agreement with the WRF-simulated cloud and aerosol properties. Higher aerosol concentration led to suppressed drizzle and increased cloud water content; that in turn les to larger radiative cooling rates at cloud top, enhanced vertical velocity variance, and increased vertical and horizontal […]